Hydraulic travel modulation control



Jim? 27, '1944. E..A. RocKwELL 2,352,344

HYDRAULIC TRAVEL MODULTION CONTROL Filed Deo. 7, 1940 2 sheets-sheet 1 lll Wl,

2 Sheets-Sheet 2 Y `E. A. RoKwr-:LL

HYDRAULIC TRAVEL MODULATION CONTROL Filed 1290.7, 1940 June 27, 1944.

INVEN-ron V.lnrohNEY um w..

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Patented slune 2?, i944 s .rareza eterea adware a noemen, West Hartford, comi.

.application December 7, 1940, Serial No. 369,003

y Claims.-

My invention relates to an apparatus for controlling the application of pressures to a part to be moved so as to obtain the desired amount of travel in the control of said part and also so as to apply any desired modulated pressures thereto. I

The object of my invention is to provide an apparatus of the above `character,'which is applicable to the control ot a part to be moved for any desired purpose, as for example so as to obtain accurate controls of steering gears, locomotive reverse gears and valve cut-oils, or for any other desired purpose, and so as to prevent.v

undesired oscillation or limiting of the part to be moved. A further object is to apply any deaired modulated pressure at any point of travel .of the part to be moved. AA further object is to provide an apparatus of this character in which the 'modulated pressues are applied n'ot onlyin the advance of the part in one direction but in the withdrawal of Asaid part by a movement in the opposite direction. Another object is to accomplish this purpose by means o one or more hydraulic valves, which preferably are in iixed position and which, also, can be placed at any desired point irrespective of the travel of the part to be moved, and so that, if desired, the monitor device connected to the valves can be placed at any otherdesired point and directly connected to thev part to be moved. Still another object is to provide such an apparatus which may be controlled manually or by any desired mechanism but in which the controllinglelement has work-performing part. Further objects of my invention will appear from the detaileddescription of the same hereinafter.

My invention is capable of 'embodiment in many different forms but by way of illustration I have shownonly two forms thereof in the accompanying drawings in which- Fig. 1 is a diagrammatic vertical section of ay admission and escape of pressure liquid riorthe lsubstantially the same degree of travel as the l cylinder 4 by bolts Il).

Fig. 3 is an assembly drawing of the system containing the form of the invention shown in Fig. 1, and which is applicable likewise to the modication shown in Fig. 2.

In the drawings, referring rst to Figs. 1 and3, I have shown amanually actuated lever I having a handle 2 which, however, may be operated by any desired moving element, moved mechanically or otherwise, said lever I being carried on a pivot 2a in a lateral extension 3 on a cylinder lt in which there is arranged to reciprocate a piston 5. Said piston 5,. on its lower end, has an .eX- tension 6 provided with a slotI in which a rounded end 8 of the lever I is carried. The piston 5 is retained in place by a head 9 connected to the Furthermore, the said piston 5 has an annular recess il carrying a `seal I2, U-shaped in cross section, of rubber or any other desired material. Within the said piston 5 there is a cylindrical chamber I3 in which a head I4 .of a rod I5 is movably carried, said rod LI5 passing out through a small hole l@ in the upper end ofthe piston 5. The said rod I5, on its upper end, carries a valve member I1 having a conical valve I8 on the end thereof, seating on a valve seat I9 in a passageway 20, in the cylinder 4, having ilutes 2l to provide passageways for the liquid around the valve member Il'. A spring 22, around the rod I5, keeps the valve member I1 fully extended upwardly as far as permitted by the head I4. A further spring 23, to retract the piston 5, .is supported on the upper end gf the piston 5 and rests, at the other end of the spring,.-.on:a.shoulder 24 on the interior of the vcylinder 4. The top of the cylinder 4 has a passageway 25 communicating with the valve seat I9 and leading to a bent pipe 26 for permitting the return of discharged hydraulic liquid by a pipe 2`|` to any desired system for the storage and placing under pressure of the returned liquid so as to thereafter supply the liquid under pressure advance of the' work-performing part and another for modulating the admission and-escape of the pressure liquid applied forthe movement of the work-'performing part in a reverse direction; p Fig. 2 isa similar view of a modied form thereof showing only a single-valve element for modulating the admission and escape of the mod ulated-pressure liquid; and, l

for the operation of the apparatus, as hereinafter described.. ,l

This may comprise, :for example, the apparatus shown for this purpose and described in detail in my patent upon Electroflow .power supply system, No. 2,136,638, granted November 15, 1938.

This I- haveshown diagrammatically in Fig. 3

herein. For this-purposef'the pipe `2I may go to'. a fillerItank 21a, having a vented filler cap 21h,

connectedhby agpipe 21ev to an accumulator 28,

Aconnectedto an electric motor 29, a pump 3c driven by said motor, a high chamber 13|, and a supply -pi'pe pressure storage. 32 for the high turn has branches and 36 leading, respectively,

to the upper ends of valve-operating cylinders Y. 31 and 38 in a dual valve casing 39.

The cylinder 31 carries a plunger 48 having a head 4| thereon provided with a flat outlet valve seat 42 for cooperation with a valve surface 43 on a tubular valve 44 provided with a chamiered .edge 45 for making the diameter of the valve seat 43 smaller than the diameter of the seating point o1 a conical high pressure inlet valve 46 on the tubular valve 44 cooperating with a valve seat 41 in the casing 39, which valve seat` 41 is in turn smaller in diameter than a lower end 48 of said tubular valve member 4. The valve 42, 43 is located in an exhaust chamber 49 which is connected by a pipe 49a to the pipe l21. The valve 46, 41 is located in a high pressure chamber 58 which i's'connected to the pipe 32 and in said chamber 58 there is a spring 5| for normally keeping the conical valve 46 seated.

The high pressure liquid receivedfrom the pipe 32 and admitted past the conical valve 46 when unseated by the manual pressure exerted on the plunger 48.to close the valve 42, 43, passes through holes 52 to a cylindrical passageway 53 -within the tubular valve 44 and thence into an end chamber 54 in 4the casing 39 in which the end 48 of the tubularl valve is received and from this point the modulated .high pressure liquid which has been admitted to the chamber 54 by thevvalve 46, 41 passes downwardly by a pipe 55 to a cham' ber 56 within a head 51, connected to a.V ixed pivot by an eye in a bossv51a, on a, Work cylinder 58 to which it is fastened by bolts 59.

The said head 51, furthermore, is connected to one end of'the pipe 33 containing theliquid under manual pressure so as to communicate with a cylindrical chamber 60 having at its rear end an air bleeder valve casing 6| provided with a valve seat- 6| a on which there is normally seated a conical bleeder valve 62carried on a bleeder valve stem 63 which has a screw thread 64 and a squared head 65 forsecuring it in the bleeder valve casing 6|. The stem 53,- furthermore, has

a transverse passageway 66 communicating with a longitudinal passageway 61 leading to an internally I screwthreaded chamber 68 normally closed by a screw 89. y

, In the chamber 68 there is carried a stationary tube 18 having 'a longitudinal passageway 1| communicating with an annular channel' 12 by Furthermore, the head 19 is connected by a pipe 85 to a chamber 86 for receiving a head 81 on a plunger 88 carried in the cylindrical chamber 38. The said head 81 has a flat high pressure inlet valve seat 89 cooperating with avalve surface 98 adjacent to a chamfered edge 9| on the upper end of a tubular reverse modulation valve 92 which is adapted to be moved by the plunger 88 within a cylindrical passageway 93 in the casing 39. The said passageway 93 has therein an outlet valve seat 94 against which a conical valve 95 on the tubular valve member 92 is adapted to seat. The conical valve 95 is normally moved into seated position by a spring 96 in a chamber 91 in the casing 39 which communi- -cates by a passageway 98 to the chamber 49.

Also, said tubular valve member 92 has a longitudinal passageway 99 leading to an end chamber |88 connected by a passageway I 8| to the high pressure chamber 58. The chamber |88 also receives a lower end |82 of the tubular valve member 92 which is larger in diameter than the valve seat 94, which in turn is larger than the valve surface 98.

The modification of my invention shown in Fig. 2 is constructed substantially the same as the form of my invention 'shown in Figs. 1 and 3 except that in this instance the tubular valve 92 and appurtenant parts thereof are omitted and except that in this instance the piston 15 is retracted by a spring |83, located within the Work cylinder 58. Also, in this modification of my invention the pipe 85 is omitted and replaced by a vent |84.

In the operation of the form of my invention shown in Figs. 1 and 3, when the manual con--v trolling lever is pressed downwardly this will close the valve |8`, I9, trapping the liquid in the cylinder 4, which will then be forced downwardly through the pipe 33 and into the cylinder 14 according to the position where the piston 15 is located owing to the resistance which is exerted by the part to be moved to perfonn work, 83. The cylinder 14 insures that the travel of the part 83 will be substantially the same as the travel of the hand lever At the same time the manual pressure upon the liquid in the pipe 34 will close the valve 42, 43 as well as the valve 89,

. 98 so as to unseat .to the desired extent the valve 46, 41 and the valve 94, 95. However, the high pressure normally acting on the lower face o! the plunger 88 as compared with the lower pres- '.sure acting beneath the plunger 44 in the onmeans of .holes 13 and thence with tl'ie pipe 33.

The said tube 18, furthermore,- is located within a cylinder 14 extending` longitudinally in a plunger 15 having forward and rear s'alsv18 and 11, respectively, to seal the plunger 15 within the work cylinder 58. 'Ihe said plunger 15, further-- more, has a stem 18 which passes out through a head 18 secured by'bolts 88 ,to the worl-rr cylinder '58. The head 19`has a seal 8| held in place by a tubular screw 82. -The end of the stem 18 is modulation will cause these valves to open and close somewhat diilerently, and the same is true in theV reverse manner in the off-modulation. Accordingly, the high pressure liquid in the pipe 32 will pass through the holes 52 into the passageway 53 and thence through the pipe 55 to the left face of the piston 15, thus applying any desired amount o1'v pressure towards the4 right on the work-performing piston 15. It will be understood that as the work is advanced for any connected to a screw-threaded eye-member 83 having an eye 84 to enable it to be connected to any desired part to be moved, for. the performance of work.

reason, the piston 15 will be moved up accordingly by the pressure liquid from the pipe 55, but

irrespective of whether the work advances or remains stationary and irrespective of the position of the piston 15, any desired degree oi' pressure o n the work is attainable corresponding to the amount of high pressureI liquid admitted to the pipe 55 from the inlet valve 48, 41 and when any such desired pressure is attained the reaction of the pressure .applied will cause the valve 45, 41 to close until some further increment of liquid is admitted fOr Obtaining an increased pressure.-

Whenthe desired degree of movement ofthe lever I (which. is proportional to the movement. vof the piston is attained and the lever I is n just enoughto increase the volume 0f the chamber 14% so that the pressure force acting on the pistons 40, 88 due to the uid pressure in the pipes 33, is lowered and the valves 46 and 95 close and move the means and VBil'back in their chambers, the fluid pushed back. by means 40' andv @t iiowing in the space created in the chamber 'it by moving the piston 15. As the valves 46 and 95 close, the piston 15 movement ceases. This is accomplished at all times by obtaining a "feel on. the hand-lever I coordinate tothe pressure that has been admitted to the pipe for the performance of. workwhich is due to the upwardly directed pressure on the central face of the piston Mi and the peripheral lower face of the piston 88, when the valves 4I and'89 are in closed position. Also, the 'amount of travel of the piston 'i5 forthe performance of work will be approximately coordinate to the amount of travel of the hand lever I. Also, if the pressure is'applied rapidly by the lever I, a'corresponding fast movement of the Ypiston 15 will be obtained and a high effective force ;will be produced by this quick.

movement of the lever I. While this movement of the piston 15 tothe rightis taking place there is a coordinate release of pressure-liquid from the right end of the cylinder 58 by the pipe 85 and it will be understood that any increments of pressures applied through the pipe 55 to the left face from the right face-of the piston 15 due to the reverse modulating valvel member 92 connected with the pipei85. In other words, similar presliquidthe piston 15 will be actuated to exert the desired modulated force, either to the right or to the left, as desired, and while the said piston 15 is caused to advance or be retracted or to be maintained at any desired point in its travel it will be caused to follow positively the movement of the manual lever I and to be maintained in any of these positions by positively exerted pressures of the hydraulic liquid -on both faces of said 'piston simultaneously. Also, the hand lever and thel part moved toperform work will'remain in 'ci the piston-l5 will be accompanied by'acoordinate escape of incrementsof the pressure liquid sures will be obtained on both faces 'of the piston i5 in any one static position'thereof and at any one degree of pressure desired to be applied, .it being understood that at'any such static position all the valves B2, 43 and I6, 41, as well as 89, 90 and 94|, @35, will be in closed position. This is accomplished, as before stated, inasmuch as the opening oi the high pressure inlet valve 46, 41, as above described, to admit an increment of the high pressure liquid to the left face of the pistonv 'di willbe accompanied'by a simultaneous opening or the release valve 94, 95, tov release to the same extent the high pressure liquid which is normally present on the right face of. the piston I5, this action takngplace until the differential pressure applied to each of 'the tubular valve members 'dd and 92- causes the valves '66. 41 and $3.5 to close. closed and, therefore, the high pressure liquid normally passes from' the passageway IBI through the tubular passageway 99 and the normally open valve de, ii@ through the pipe 85 to the right face oi the pistoni. The oil modulation of the operation of the'valve member i4 and 92 willoperate inthe reverse manner. release of increments of pressure liquid by the 'partial opening of the valve 62, 43', the valve di?, @Il will be partially opened, thus causing incre-` ments of the high pressure liquid to pass from the chamber IDI) through the passageway 99`and i the pipe 95 'to the right faiceof the plunger 15,

which will be accompanied by the escape of corresponding increments of high pressure liquid throughthe pipe 55, passageway 53 and pipe 49o. Vhus, in either the on or off modulation of the In the case of the- The valve 94, 95 is normally step, as even .when the hand lever I is withdrawn and then operated again, both will start the work performing action at the same point where it had previously been'interrupted.

The operation of the modification of my invention shown' in Fig. 2 is the same as described in connection with Figs. 1 and 3, except that in this instance the tubular valve element 92 and valves associated therewith are substituted by the presence of the spring ID3, which brings about the retraction of thepiston 15. In this instance the pipe acts as a breather connection from` the right face of'the piston I5, which is connected'thereby to thevpipe 49a by means of the chamber 49. However, in this instance there is also present both an on' and off modulation of liquid from'the left face of the piston 15 in the advance and retraction 'ofsaid piston.

It will be understood, of course, that any gas- Veous iluid may be used in place of the hydraulic liquid herein, although not so advantageously as where'hydraulic liquid is used.

While I have described myA invention above in detail I wish it to be lunderstood that many changes 'may be made therein without departing 'from the spirit of the same.- l

I claim:

l. In combination. a source of iiuid under pressure, an element adapted to be moved thereby, and iluid pressure means for actuating the same comprising a controlling device, a valve adapted to apply, by modulated increases of pressure, a iluid pressure for urging said element in one direction and a second valve adapted to corre-v spondingly release, by modulated amounts of pressure, a huid pressure which urges said element in the opposite direction, said first valve containing a normally closed high pressure inlet valve element and said second valve comprising a normally closed outlet valve element. said two .valves containing also, respectively, a normally open outlet valve and a normally open high pressure inlet valve, both of said last-mentioned valves `having a iduid pressure connection to said controlling device. A y

2. In combination, a source of liquid under pressure, an element adapted to be moved thereby, and hydraulic means for actuating the same comprising a controlling device, a valve adapted t0 apply, by modulated increases of pressure, a hydraulic pressure for urging said element in one direction and a second valve adapted to correspondingly release, by modulated amounts of pressure, a hydraulic pressure which urges said element in the opposite direction, said valves being constructed to apply to said element anA increase of the amount of liquid applied from either of said valves and a corresponding de- .crease of the amount of liquid from the other v valve, said ilrst valve -containing a normally closed high pressure inlet valve element and said second valve comprising a normally closed outlet valve element, said two valves containing also,

respectively, a normally open outlet valve and a normally open high pressure inlet valve, both of said last-mentioned valves having a hydraulic connection to said controlling device.

3. In combination, a source of iluid under pressure, an element adapted to be moved thereby, and means for actuating the same comprising a controlling device, a valve adapted to apply, by modulated increases of pressure, a fluid pressure for urging said element in one direction and a second valve adapted to correspondingly release, by modulated amounts of pressure, a fluid pressure which urges said element in the opposite direction, said rst valve containing a normally closed high pressure inlet valve element and said second valve comprising a normally closed outlet valve element, said two valves containing also, respectively, a normally open outlet valve element and a normally open high pressure inlet valve element, both of said last-mentioned valve elements having a fluid pressure connection to said controlling device and a fluid pressure connection between the outlet valve elements of said two valves.

4. In combination, a source of liquid under pressure, an element adapted to be moved thereby, and means for actuating the same comprising a controlling device, a valve adapted to apply, by modulated increases of pressure, a hydraulic pressure for urging said element in one direction and a second valve adapted to correspondingly release, by modulated amounts of pressure, a hydraulic pressure which urges said element in the opposite direction, said valves being constructed to apply to said element an increase of the amount of liquid applied from either of said r valves and a corresponding decrease of the amount of liquid from the other valve, said first valve containing a normally closed high pressure inlet valve element and said second valve comprising a normally closed outlet valve element, said two valves containing also, respectively, a normally open outlet valve element and a normally open high pressure inlet valve element, both of said last-mentioned valve elements having a hydraulic connection to said controlling device and a hydraulic connection between the outlet valve elements of said two valves.

5. In combination, a sourceof uid under pressure, an element adapted to be moved thereby, and iluid pressure means for actuating the same comprising a controlling device, a valve adapted to apply, by modulated increases of pressure, a fluid pressure for urging said element in one direction and a second valve adapted to .correspondingly release, by modulated amounts of pressure, a fluid pressure which urges said element in the opposite direction, said flrst'valve containing a normally closed high pressure inlet valve element and said second valve comprising a normally closed outlet valve element, said two valves containing also, respectively, a normally open outlet valve element and a normally open high pressure inlet valve element, both of said last-mentioned valve elements having a fluid pressure connection to said controlling device, a fluid pressure connection between the outlet valve elements of said two valves, and a uid release conduit connected to said-lastmentioned fluid pressure connection and to said controlling device. v

6. In combination, a source of liquid under pressure, an element. adapted to be moved thereby, and hydraulic means for actuating the same comprising a controlling device, a valve adapted to apply, by modulated increases of pressure, a hydraulic pressure for urging said element in one direction and a second valve adapted to correspondingly release, by modulated amounts of pressure, a hydraulic pressure which urges said element in the opposite direction, said valves being constructed to apply to said element an increase of the amount of liquid applied from either of said valves and a correspending decrease of the amount of liquid from the other valve, said rst valve containing a normally closed high pressure inlet valve element and said second valve comprising a normally closed outlet valve element, said two valves containing also, respectively, a normally open outlet valvev element and a normally open high pressure inlet valve element, both of said lastmentioned valve elements having 'a hydraulic `connection to said controlling device, a hydraulic connection between the outlet valve elements of said two valves, and a liquid conduit connected to said last-mentioned hydraulic connection and to said controlling device.

7. In combination, a source of liquid under pressure, an element adapted to be moved thereby, and hydraulic means for actuating the same comprising a controlling device, a vhydraulic chamber connected to expand with the movement of said element and connected to said controlling device, a valve adapted to apply, by modulated increases of pressure, a. hydraulic pressure for urging said element in one direction and a second valve adapted to correspondingly release, by modulated amounts of pressure, a hydraulic pressure which urges said element in the oppositedirection, said rst valve containing a normally closed high pressure inlet` valve element and said second valve comprising a, normally closed outlet valve element, said two 'valves containing, also, respectively, a normally open outlet valve and 'a normally open high pressure inlet valve, both of said last mentioned valves having a hydraulic connection to said controlling device.

8. In combination, a source of liquid under pressure, an element adapted to be moved thereby, and hydraulic means for actuating the same comprising a controlling device, a hydraulic chamber connected to expand with the movement of said element and connected to said controlling device, a valve adapted to apply, by modulated increases of pressure, a hydraulic pressure for urging said element in one direction and a second valve adapted to correspondingly release, by modulated aniounts of pressure which urges said element in thefopposite direction, said valves being constructed to apply to said element an increase of the amount of liquid applied from either of said valves and by, a piston connected thereto, and hydraulicv means foractuating the same comprising a vcontrolling device, a hydraulic chamber in said piston connected to expand with the movement of pressure, a hydraulic assaut ond valve adapted Vto correspondingly release, by

modulated amounts of pressure, a hydraulic pressure which urges said element in the opposite direction, said first valve containing a normallyi closed high pressure inlet valve element and said second-valve comprising a normally closed outlet valve element, said two valves containing also,

respectively, a normally open outlet valve anda normally open high pressure inlet valve, both of said last mentioned valves having a hydraulic connection to said controlling device.

10. In combination, a so'urceof liquid under pressure, an element adapted to be moved thereby, a piston connected thereto, and hydraulic means for actuating the same comprising a controlling device, a hydraulic chamber in said piston connected to expand with the movement of hydraulic pressure for y said element and connected to saidvccntrolling device, a valve adapted to apply, .by modulated increases of pressure, a hydraulic pressure for urging said element 'in one direction and a second valve adapted to correspondingly release, by modulated amounts of pressure, a hydraulic pressure which urges said element in the opposite direction, said valves being constructed to apply to said element an increase of the amount of liquid applied from either of said valves and a corresponding-decrease of the amount of liquid from the other valve, said rst valve containing a normallyclosed high pressure inlet valve element andv said second valve comprising a normally closed outlet valve element. said two valves containing also, respectively, a normally open outlet valve 'and' a normally open high pressure inlet valve, both of said last mentioned valves having a hydraulic connection to said controlling device.

ED'WARDIM Rocxwnrn 

